The following contains spoilers for Titans Season 4, Episode 4, "Super Super Mart," now streaming on HBO Max.
Titans has never veered away from making big changes from its source material, and the series has done it again. A lot of history was shown about Brother Blood and Mother Mayhem, including that she is his biological mother. Yet, more shocking than that was that Brother Blood a.k.a Sebastian Blood is also Raven's half-brother and son of Trigon. He is a child of a dark prophecy, and his presence in Metropolis will be nothing but trouble for the Titans and their friends at S.T.A.R Labs.
In the comics, Sebastian became Brother Blood by murdering his father when he was still young. This was a prerequisite for becoming the leader of the Church of Blood. Titans has changed that and replaced patricide with a deeper conspiracy surrounding Trigon and Raven. Much of the first season focused on Raven and her father. The Titans thought that he was defeated and his followers scattered. Yet, it appears that Mother Mayhem is bringing them back, except this time Raven will not lead the way, her brother will.
Brother Blood and His Mother Mayhem
Season 4, Episode 4, "Super Super Mart," uncovered a lot about Brother Blood and his mother, in between fights with a resurrected Deathstroke and rehashing old plots. Mother Mayhem was chosen to become a bride of Trigon, just like Rachel's mother. She loved Trigon with an undying devotion and wanted to serve him and his prophecies. Yet, when her child was born, it was a boy. She became full of rage when "The Organization" decided to kill her newborn son, and they locked her in a deep cell. But she continued to believe that her son, Sebastian, was a child of prophecy and would help serve Trigon's wishes.
This is almost identical to Raven's own origin story. Both children were shielded from their dark fates by being taken away from The Organization. It seems like the ending of their stories is the only thing that will be different. Raven chose to be better than what fate wanted for her. She "killed" her father and created a new destiny for herself. Sebastian will likely end up being a villain. He will become consumed by his heritage and want to bring darkness to the world, just like his father. He is truly the anti-Raven, and it just so happens that he is her brother.
Which Fate Will Brother Blood Chose?
Raven is currently free of Trigon's influence because Mother Mayhem stole her power. It's clear that she intends to give that power to her son in service of Trigon. Brother Blood will face the same decision that Raven did back in Season 1 -- give in to the darkness or defy it. Unfortunately, it seems far more likely that Brother Blood won't choose the noble path like Raven did. He may give into the darkness and allow Trigon to come back to the world. This will give Titans a chance for redemption after the misstep of using Trigon at the opening of Season 2.
Brother Blood and Raven being siblings is a convenient twist of fate. Their stories match up and are two sides of the same coin. Both are children of a dark prophecy, but while one has chosen to dedicate herself to helping people, the other seems to be leaning toward creating pain and suffering. It will be interesting to see if Raven can take on her own family and stop the destruction of the world again.
New episodes of Titans air Thursdays on HBO Max.